This document describes electrical and mechanical requirements of single-phase station service voltage transformers with system voltages of 46 kV or higher and with the maximum rated voltage of the power winding of 1 000 V. This document is a basis for the establishment of performance and limited electrical and mechanical interchangeability requirements of the equipment are described. It is also a basis for assistance in the proper selection of such equipment. A station service voltage transformer (SSVT) is a single-phase transformer to be connected line-to-earth on an effectively earthed system. It can be used either as an individual unit for supplying single-phase loads, or in a three-phase bank to support three-phase loads. A typical application is to supply substation power such as lighting, pump and motor loads. The SSVT can be provided with a measuring winding when requested by the user.

This Standard is a basis for the establishment of performance and limited electrical and mechanical interchangeability requirements of the equipment described. The Standard also provides assistance in the proper selection of such equipment.